1. Field of the Invention
The invention relates to an cartridge mounted on an image forming apparatus such as a copying machine or a printer for forming an image by the use of a recording technique of the electrophotographic type, the electrostatic recording type or the like.
2. Description of Related Art
As a cartridge mounted on an image forming apparatus, there is, for example, one which comprises a photosensitive member, a charger, a developing device and a cleaner made into a unit. Besides this, there is one which is divided into a cartridge holding a photosensitive member and a cartridge holding a developing device.
As described above, the main portion of the image forming apparatus is made into a simply interchangeable cartridge and thus, even an ordinary user can effect the maintenance of the apparatus.
In present day image forming apparatuses, a powdered toner is generally used as a developer for depicting an image on recording paper. Because of being powder, the toner is liable to leak and particularly, a cartridge containing the toner therein is given vibration by the user handling and therefore the toner is liable to leak therefrom. For this reason various contrivances have been made so that the toner may not leak.
FIG. 27 of the accompanying drawings shows a cross-sectional view of a cartridge P which will be instructive for understanding the present invention. This cartridge P carries therein, as main constituents, a photosensitive member 103, a charging roller 104 for charging the photosensitive member 103, a developing roller 105 bearing thereon a toner for developing an electrostatic latent image formed on the photosensitive member, a cleaning blade 106 abutting against the photosensitive member to thereby clean the photosensitive member, and a shutter 107 for protecting the photosensitive member. The reference numeral 108 designates a toner containing chamber, the reference numeral 109 denotes a developing chamber, the reference numeral 110 designates an opening for connecting the toner containing chamber and the developing chamber together, the reference numeral 111 denotes a seal for closing the opening 110 (this seal is stripped off when the cartridge begins to be used), the reference numeral 112 designates a layer thickness regulating blade (developing blade) for regulating the layer thickness of the toner formed on the developing roller 105, and the reference numeral 113 denotes end portion seals for preventing the leakage of the toner from the opposite ends of the developing roller.
FIG. 29 of the accompanying drawings is an exploded view and an assembly view of a frame forming the toner containing chamber and the developing chamber. As shown in FIG. 29, the toner containing chamber and the developing chamber are formed by superposing frame parts 101 and 102 made of synthetic resin one upon the other. The frame parts 101 and 102 are coupled together by a coupling method such as ultrasonic welding, whereby the leakage of the toner from the gap between the two is prevented.
Now, the developing blade 112 comprises a blade 112a made of rubber and attached to a support member 112b made of a metal by such means as adhesive securing, and the lengthwisely opposite end portions of the support member 112b of the developing blade 112 are fixed to the frame part 101 by screws 114. FIGS. 26A and 26B of the accompanying drawings show enlarged views of the attached portion of the developing blade. Between the frame part 101 and the developing blade 112, an elastic seal 115 such as foamed polyurethane is compressed and sandwiched as shown in FIG. 26A, or a portion 101a of the frame part 101 is caused to eat into the blade 112a as shown in FIG. 26B, to thereby prevent the leakage of the toner from between the developing blade 112 and the frame part 101.
FIG. 28A of the accompanying drawings is a cross-sectional view of the lengthwisely central portion of a cartridge, and this cartridge somewhat differs in shape from the cartridge shown in FIG. 27, but is substantially the same as the cartridge of FIG. 27 in the structure of the attached portion of the developing blade. The reference numeral 116 designates a toner agitating member provided in the toner containing chamber, and this toner agitating member 116 is rotated so that the tip end 116a thereof may describe a locus indicated by dot-and-dash line. Although not shown, on the left side of FIG. 28A, the photosensitive member, the cleaner, etc. are mounted as in FIG. 27.
When as shown in FIG. 28A, the user holds the cartridge in his hand H, the frame is sometimes deformed by the force thereof as shown in FIG. 28B of the accompanying drawings. When the frame is deformed, a gap is created between the developing blade 112 and the frame part 101 as shown in FIG. 28B, and in the case of the seal construction as shown in FIG. 26B, the toner leaks from this gap (this gap is largest in the central portion of the developing blade which is not fixed by a screw because the lengthwisely opposite ends of the developing blade are fixed to the frame by the screws 114). Even when the elastic seal 115 is sandwiched between the developing blade 112 and the frame part 101 as shown in FIG. 26A, a gap may be formed between the elastic seal 115 and the developing blade 112. Also, even if a gap is not formed and the leakage of the toner can be prevented, a portion of the frame part 101 may contact which the toner agitating member 116 mounted in the toner containing chamber 108 due to the deformation of the frame part 101 and may damage the tip end 116a thereof. Even when due to the deformation of the frame, the toner agitating member and the frame do not interfere with each other, the deformation of the frame is not preferable in the sealing performance of the cartridge. It would occur to mind to make the thickness of the frame great in order to prevent the deformation of the frame, but this method will result in the increased weight of the cartridge.
In the case of the cartridge handled by the user, as described above, the compatibility of the increased sealing performance between the blade member and the frame and the increased rigidity of the frame is required.
The present invention has been made in view of the above-noted problem and an object thereof is to provide a cartridge which achieves the compatibility of the increased sealing performance between a blade member and a frame and the increased rigidity of the frame.
Another object of the present invention is to provide a cartridge which achieves the compatibility of the increased sealing performance between a blade member and a frame and the increased rigidity of the frame by a simple method.
Still another object of the present invention is to provide a cartridge comprising:
a frame; and
a blade member held by the frame;
wherein a double-sided adhesive tape is stuck between the frame and the blade member along the lengthwise direction of the blade member.
Further objects of the present invention will become apparent from the following detailed description when read with reference to the accompanying drawings.